Britain allowed firms to sell chemicals to Syria capable of being used to make nerve gas, the Sunday Mail can reveal today.

Export licences for potassium fluoride and sodium fluoride were granted months after the bloody civil war in the Middle East began.

The chemical is capable of being used to make weapons such as sarin, thought to be the nerve gas used in the attack on a rebel-held Damascus suburb which killed nearly 1500 people, including 426 children, 10 days ago.

President Bashar Assad's forces have been blamed for the attack, leading to calls for an armed response from the West.

British MPs voted against joining America in a strike. But last night, President Barack Obama said he will seek the approval of Congress to take military action.